A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Position-Finding
From: Robert Eno
Date: 2005 Jun 7, 23:35 -0400
I had a quick perusal through successive issues of Bowditch, starting from 1926 and working my way foward through time. It was not until I reached the 1966 reprint of the 1962 edition, that I found an abbreviation listed on page 65, as follows: "mi., M". On page 986 of the same edition, under chart symbols, the abbreviation is given as: "M". The 1984, two-volume Bowditch provides the same abbreviation on page 63, volume 1. On page 1163 of the same publication under Appendix A: Abbreviations, it is listed as "NM" and "n. mi". Moving on to Dutton's (14th edition) Section A, page 3 (at the end of the textbook) provides several possibilities: "M" "Mi" "NMI" & "NM". The 12th edition of Dutton's indicates that it is simply "M". In the 1955 edition, Volume 1 of the Admiralty Manual of Navigation indicates that: "...Except on charts where the symbol M is now adopted, the unit is always denoted by a ', which is also the symbol for a minute of arc". British Publication, AP 1234, Air Navigation (Air Ministry, 1944) gives it as "n.m." By the look of it, you can take your pick. I find it rather odd that such an important unit of measure would not have a clearly unique and universally-accepted symbol. It is a real mixed bag. I generally use "nm" or "NM", depending on my mood that day. cheers, Robert ----- Original Message ----- From: "John Kabel"
To: Sent: Tuesday, June 07, 2005 10:58 AM Subject: Abbreviation of Nautical Mile > An interesting question came up the other day as we were editing a course > on Electronic Charting. What is the accepted abbreviation of "nautical > mile"? We need a standard that can be applied across all Canadian Power > and Sail Squadron courses. > > I did some searching and came up with the following, to start the > discussion: > > - Bureau International des Poids et Mesures notes that there is no > accepted > symbol, though all agree on the distance measured (1852 metres) > - neither the Canadian Metric Practice Guide nor the CSA publication > International System of Units have an abbreviation in their tables > - Wikipedia (the online encyclopedia) suggests that "nm" is preferred, > especially in aeronautics > - Canadian Hydrographic Service uses "M" in its Abbreviations > - The NOAA Chart 1 (Abbreviations) lists all of "M", "Mi", "NM" and "N M" > for "nautical mile(s)" > - Nav Canada, the agency responsible for air traffic control in Canada, > uses "NM" > - Bowditch (1995) gives both "n.mi." and "NM" in Abbreviations and > Acronyms > > So, what does the group think? What is USPS usage? What is Navy usage? > Please reply either to the list or to me privately. > > Thanks. > > John Kabel > London, Ontario > > > -- > Outbound e-mail is scanned for viruses. > Checked by AVG Anti-Virus. > Version: 7.0.323 / Virus Database: 267.6.4 - Release Date: 6/6/05